26-12
Ethernet Card Software Feature and Configuration Guide, R7.2
January 2009
Chapter 26 Configuring IEEE 802.17b Resilient Packet Ring
Configuring Protection Timers
To enable and configure forced or manual switching, perform the following procedure , beginning in
global configuration mode:
Configuring Protection Timers
Protection messages are sent based on the intervals of two timers. T hese timers apply under different
circumstances:
• Fast timer—Immediately after a protection event occurs, a fast protection timer is used. This ti mer
is configured between 1 and 20 milliseconds to cause a rapid acknowledgement of the protected state
on the ring. A finite number of packets are sent at this frequency a fter the event. The default for this
timer is 10 milliseconds.
• Slow timer—Between protection events, the slow timer communicates the current protection state
of the ring. This timer is configured from 1 to 10 in units of 100 milliseconds. The default is 10,
which represents 100 milliseconds.
The protection timers are configured the same on both spans of an interface.
Command Purpose
Step 1 Router(config)# interface rpr-ieee 0 Activates interface configuration mode to
configure the RPR-IEEE interface.
Step 2 Router(config-if)# rpr-ieee protection
request {forced-switch | manual-switch}
{east | west}
Specifies that a switch take place on the interface:
forced-switch—Precedes all other failure events
on a ring for the span on which it is configured.
The operation protects the span indicated by the
command. In the case of steering, forwarding uses
only the topology list for the opposite span. A
forced switch is saved in the configuration.
manual-switch—Behaves similarly to a forced
switch, in that it coerces a reaction from the
protection system. The difference is that this
configuration can be usurped by higher-level
requests detected on the configured or the opposite
span. A manual switch is not saved in the
configuration. Configuring a manual Swich on a
span that has a forced switch configured wiil clear
the forced switch.
Note When a manual switch is configured, it
will neither display in the running
configuration nor save to the startup
configuration.
You must specify whether the switch is to take
place on the east or west ringlet.
Step 3 Router(config)# no shut Enables the RPR-IEEE interface and changes the
mode from the default passthrough.
Step 4 Router(config)# end Returns to privileged EXEC mode.
Step 5 Router# copy running-config startup-config (Optional) Saves configuration changes to the
TCC2/TCC2P flash database.